Threading devices



Dec. 20, 1955 1 MEISSLER THREADING DEVICES Filed Feb. 9, 1955 UnitedStates Patent O TrrREADlNG DEVICES Ludwig Meissler, Kaiserslautern(Pfalz), Germany, as-

siguor to G. M. Pfaif A.G., Kaiserslautern (Pfalz), Germany ApplicationFebruary 9, 1953, Serial No. 335,723

Claims priority, application Germany June 30, 1952 4 Claims. (Cl.112-225) This invention relates to threading devices for sewing machinesand is more particularly concerned with an improvement of the threadingdevices covered by United States Patent No. 2,704,526 assigned to thesame assignee.

In the threading device in accordance with said previous application,the engagement element, which is secured to the guiding bar of thethreader, for example, a pin which during operation of the threaderengages a plane on the needle bar socket or on a ring member secured tothe needle bar, is guided in a groove which is either defined by theneedle bar rod and a disk or is formed in the ring member.

In one embodiment of that invention the accurate position of theengagement element when contacting the engagement plane is insured by apressure spring which is disposed around the guiding bar between a lowerbearing on the sewing machine head and the clamp member which carriesthe threading hook.

In the embodiment referred to the spring is visible and readilyaccessible between the head portion of the sewing machine and the clampmember. That is a disadvantage, not only as far as appearance andpossible soiling are concerned, but also with respect to the assembly ofthe threader.

It is, therefore, the object of the present invention to improve thearrangement in accordance with the said disclosure by employing novelmeans in place of the said spring. For that purpose the needle baroscillator is provided with guiding means for the engagement member. Inthis manner it is avoided that during downward movement the guiding barof the threading device turns and that possibly the threading hookknocks against the needle clamp.

'Ihe guiding means is advantageously in the form of a plane surfacewhich is aligned with the oblique plane on the ring member upon theneedle bar or, in another embodiment on the disk above the needle barsocket.

An illustrative embodiment of the invention is shown in the accompanyingdrawing in which Fig. 1 is a perspective view of the device inaccordance with the invention showing the device in inoperativeposition; Fig. 2 is a view of the device similar to that shown in Fig.l, but with the guiding bar and the components for operating the same inthe depressed, operative position with respect to the needle bar, andFig. 3 is a perspective view of the upper end portion of the deviceshowing the end of the guiding bar projecting through the slidingmember.

The perspective illustration clearly indicates the needle bar oscillator52, the needle bar 61, the needle bar socket 17, the ring member 64 andthe threading arrangement. Ihe needle bar socket 17 and the ring member64 are rigidly axed to the needle bar 61. The needle bar 61 with needlebar socket 17 and ring member 64 is caused to oscillate up and down inthe needle bar oscillator 52 by the pitman arm arrangement well known tothe man skilled in the art, the pitman arm having operative engagementwith the arm 17a of the socket 17. The ring 2,727,479 Patented Dec. 20,1955 ICC member 64 presents a guiding or corresponding plane 64'adjacent the upper portion of member 64. A guiding slot 65 is formed inthe member 64 adjacent to and positioned immediately below the guidingplane 64.

The guide pin 15 which is rigidly mounted in and extending through theguiding or threading bar 2 of the threader rests against a guiding plane74 of the needle bar oscillator 52 during up and down movements of theguiding bar and is thus held in the position in which it must contactthe ring member 64. During the change over from the guiding plane 74 tothe ring member 64 the effect of the spring around the guide bar 2 issuicient to' prevent the rotation of the guide bar 2. The guiding plane74 extends in the same plane as the planer64 adjacent the slot 65 of thering member 64. The slot can also be formed between the surface of theneedle bar socket 17 and a disk disposed at a suitable distance abovethe socket. Member 7 is mounted on guiding bar 2 and has its lowerportion bearing against spring 3. A lever 2t) is attached to member 7 topermit application of downward pressure thereon to move member 7 and bar2 downwardly into threading position. Formed in member 7 is a groovedtrack 16. The portion of pin 15 diametrically opposed to that portion ofpin 15 resting against guiding plane 74 is journaled in grooved track16.

ln operation, actuation of the threading device is commenced byapplication of downward pressure upon lever 20. Lever 20 pulls downmember 7 which causes bar 2 to be pulled down. Downward movement ofmember 7 compresses spring 3. The bar 2 along with pin 15 move downwardwithout any rotary motion. The portion of the pin 15 guiding against theguiding plane 74 moves downwardly with respect to plane 74. The opposedportion of pin 15 in track 16 remains stationary with respect to thetrack 16. The ring member 64, in the threading position has its plane 64immediately adjacent the lower edge of plane 74. Plane 64 therefore ismerely an extension of plane 74 and likewise permits pin 15 to movedownwardly without rotary motion. Further pressure on lever 20 causesthe threading hook to be aligned with the eye of the needle. At thispoint pin 15 drops from plane 64' into guiding slot 65, so that pin 15is now free t0 rotate. The portion of pin 15 in the track 16 follows thecurvature of the track 16 which imparts rotary motion to the bar 2causing it to rotate from right to left. This rotation swings thethreading hook through the eye of the needle into position for threadingthe needle. Release of pressure on the lever 20 restores the structureto the beginning of its operating cycle.

Having now fully described my invention I claim:

l. A threading device for the needle of a sewing machine of the typeprovided with a needle bar oscillator supported in the head of themachine, said device including a needle bar movably supported in saidoscillator, a guiding bar carrying a threading hook, said guiding barbeing disposed substantially parallel to and adjacent said needle barand slidably supported in said oscillator for longitudinal movementrelative to said needle bar, and operating means for said deviceincluding a guiding surface extending on said needle bar oscillatorproximate said guiding bar in the direction of movement of said guidingbar, a ring member mounted on said needle bar adjacent to and below saidguiding surface and presenting a guiding slot, an actuating membersecured to said oscillator and a guide pin extending through saidguiding bar, said pin having in inoperative position one end in slidingengagement with said guiding surface and having its other end inoperative engagement with said actuating member; whereby downwardpressure on said actuating member causes axial movement of said guidingbar thereby guiding said pin to said guiding slot and continued pressurecauses arcuate movement of said pin in said slot thereby impartingrotative action to said guiding bar to swing the threading hook throughthe eye of the needle.

2. A threading device for the needle of a sewing machine of the typeprovided with a needle bar oscillator supported in the head of themachine, said device including a needle bar movably supported in saidoscillator, a guiding bar carrying a threading hook, said guiding barbeing disposed substantially parallel to and adjacent said needle barand slidably supported in said oscillator for longitudinal movementrelative to said needle bar, and operating means for said deviceincluding guiding surface extending longitudinally of said oscillatorproximate said guiding bar in the direction of movement of said guidingbar, a ring member mounted on said needle bar adjacent to and below saidguiding surface and presenting a rst guiding slot, an actuating membersecured to said oscillator presenting a second guiding slot, and a guidepin extending through said guiding bar, said pin having in inoperativeposition one end in sliding engagement with said guiding surface andhaving its other end in operative engagement with said actuating memberby way of said second slot; whereby downward pressure on said actuatingmember causes axial movement of said guiding bar thereby guiding saidpin to said guiding slot and continued pressure causes arcuate movementof said pin in said first and in said second slot thereby impartingrotative action to said guiding bar to swing the threading hook throughthe eye of the needle.

3. A threading device for the needle of a sewing machine of the typeprovided with a needle bar oscillator supported in the head of themachine, said device including a needle bar movably supported in saidoscillator, a guiding bar carrying a threading hook, said guiding barbeing disposed substantially parallel to and adjacent said needle barand slidably supported in said oscillator for longitudinal movementrelative to'said needle bar, and operating means for said deviceincluding a guiding sur- 'face extending longitudinally of said needlebar oscillator proximate said guiding bar in the direction of movementof said guiding bar, a ring member mounted on said needle bar adjacentto and below said guiding surface and presenting a rst guiding slot, anactuating member secured to said oscillator presenting a second guidingslot, and a guide pin extending through said guiding bar, said pinhaving in inoperative position one end in sliding engagement with saidguiding surface and having its other end in operative engagement withysaid actuating member by way of said second slot and a biasing springdisposed around said needle bar and extending between said oscillatorand said actuating member; whereby downward pressure on said actuatingmember against the force of said spring causes axial movement of saidguiding bar thereby guiding said pin to said guiding slot and continuedpressure causes arcuate movement of said pin in said first and in saidsecond slot thereby imparting rotative action to said guiding bar toswing the threading hook through the eye of the needle.

4. A threading device for the needle of a sewing machine of the typeprovided with a needle bar oscillator supported in the head of themachine, said device including a needle bar movably supported in saidoscillator, a guiding bar carrying a threading hook, said guiding barbeing disposed substantially parallel to and adjacent said needle barand slidably supported in said oscillator for longitudinal movementrelative to said needle bar, and operating means for said deviceincluding a guiding surface extending longitudinally of said needle baroscillator proximate said guiding bar in the direction of movement ofsaid guiding bar, a ring member mounted on said needle bar adjacent toand below said guiding surface and presenting a first guiding slot, anactuating member secured to said oscillator presenting a second guidingslot, andv a guide pin extending through said guiding bar, said pinhaving in inoperative position one end in sliding engagement with saidguiding surface and having its other end in operative engagement withsaid actuating member by way of said second slot,'a biasing springdisposed around said needle bar and extending between said oscillatorand said actuating member and a manipulating lever disposed on saidactuating member; whereby downward pressure on the lever of saidactuatingmember against the force of said spring causes axial movementof said guiding bar thereby guiding said pin to said guiding slot andcontinued pressure causes arcuate movement of said pin in said rst andin said second slot thereby imparting rotative action to said guidingbar to swing the threading hook through the eye of the needle.

References Cited in the le of this patent UNITED STATES PATENTS l640,919 Kobler I an. 9, 1900 1,182,273 Hohmann May 9, 1916 2,544,577Weber Mar. 6, 1951

